This invention relates to a portable container. In one aspect, this invention relates to a portable container adapted for the transportation of refrigerated or frozen goods, e.g., groceries. In another aspect, this invention relates to a portable container equipped with an insert for holding carbon dioxide (CO.sub.2) ice, typically in snow or pellet form. In yet another aspect, this invention relates to a portable container that can convert from a container adapted for transporting refrigerated goods to a container for transporting frozen goods simply by inverting a CO.sub.2 ice-containing insert.
With the growth of the .com industry, the need to transport refrigerated or frozen goods from a central distribution center (e.g., warehouse, grocery store, etc.) to a consumer (e.g., individual, business, etc.) in an effective and efficient manner has also grown. Effective transport means that the goods are conveyed from one point to another without material diminution of their quality, and efficient transport means that the goods are conveyed quickly and inexpensively.
In the context of transporting refrigerated or frozen food stuffs, the portable container (or tote) ideally should exhibit a number of beneficial properties. The tote should be large enough to hold a reasonable amount of groceries, e.g., one or two fully packed, standard-size grocery bags, yet sufficiently light so that it does not add significantly to the total weight of the groceries. The tote should be reusable over extended periods of time, and thus resistant to the routine impact, water, solvent, temperature and similar abuse that is commonly encountered in transporting goods from once place to another. In addition, the tote should be easy to use, e.g., easily opened and closed, packed, carried, stored, cleaned, etc., and it should easily convert from a condition for transporting refrigerated goods to a condition for transporting frozen goods, and vice versa. In this regard, this desirable tote is markedly different than conventional totes which are designed for transporting only hot or cold foods, e.g., totes for delivering hot pizza or cold beverages.
Various containers are known that use an insert containing carbon dioxide ice or snow (the latter simply a shaved or aerated form of the former), but none of these embody all of the desired features described in the proceeding paragraph.
For example, U.S. Pat. No. 3,971,231 to Derry teaches a refrigerator comprising an insulated cabinet with an access opening and at least one dry ice (CO.sub.2) carrier removably disposed within the cabinet. The insert comprises perforated and nonperforated walls opposed to one another that promoted refrigerated or freezing conditions, respectively, in the space adjacent the wall(s).
Kornish et al. teach in U.S. Pat. No. 3,678,703 a container for transporting or storing packaged frozen foods. The freezing element of this container is located in the cover of the container, and the freezing element comprises a heat-absorbing medium, preferably a mixture of water and propylene glycol.
Two other food storage and cooling devices of interest are U.S. Pat. No. 3,800,554 to Knapp, et al. and U.S. Pat. No. 1,654,828 to Nelson. Both use dry ice as the cooling agent, but neither are particularly well adapted for easy transport of refrigerated or frozen grocery items. The Nelson cabinet is designed more for storage then transport, and the Knapp, et al. cabinet is designed for use in travel trailers, camper units and the like.